If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Re: My Oxalic Acid Vaporizer

Originally Posted by Daniel Y

Shadow I can't say about the anti seize and gassing. But would it matter? The threads for the glow plug at least are outside the chamber. As for off gasing of copper or brass. I have never heard a concern about it for plumbers that sweat copper all day long. often in large volumes in confined spaces. I have seen the concern that the introduction of Oxalic Acid changes the chemistry though. At the very least a concern.
I do beleive the forced movement of the vapors is more of a perception thing to the beekeeper than a necessity. But people are attracted to what they are attracted to. Vapors are goign to pretty much dissipate no matter what. But this is not something the average person is goign to know about or rely on. that it blows around just carries a level of comfort to it. I am pretty thrilled with the design as it is.

The off gassing of anything I think would be a concern. I'm just saying to please be careful. Some stuff in very small amounts can cause long term damage.

Re: My Oxalic Acid Vaporizer

Regardless of reactivity, Copper fittings are out due to price. I can actually get SS fittings at a lower or at least equal price.

The main cost with SS fitting is the Flange at $27.00 for a threaded flange. Any suggestions for the connection from the pipe to the box would be appreciated.

Otherwise I am looking at anywhere from a 1 1/4 inch nipple and 45 degree elbow down to the same in 3/4 inch. Price for the set ranging from $17.03 down to $9.01.
As a comparison a single 45 degree elbow in copper (1 1/4 inch is about $10.00) 3/4 inch is not a lot cheaper.

I priced such large fitting because the Aluminum rod I am starting with is 1 1/4 inch diameter but that is a bit overkill for the fittings.

I am looking for other solutions, preferable lower cost for the connection to the box.

Also the 45 degree elbow is threaded at both ends. I can thread the aluminum rod but would rather have this be a slip fitting for ease in removing and reloading. even if it is a slip fitting with a thumb screw as a set screw for added holding power. If nothing else I will turn and thread a piece from aluminum rod. I much prefer to come up with a design that is of the shelf parts so that anyone even without a shop can repeat it. Except for the glow plug / vaporizing chamber.

By far the big cost with these parts would be the flange. I was lookign for a bulk head adapter but am not making much ground there, plus the costs are still coming in fairly high.

Anyway so far my parts woudl run between $55.37 to $36.01 all stainless steel not including the aluminum chamber or shipping. That heats the tar out of $175 I have heard mentioned for other systems. Still let me know what you all think of that sort of cost. With a little more effort I think we can put a dent in that cost with a solution to the SS flange. I am looking for a brass flange since at this point the brass will not be exposed to the acid vapor. but am not having a lot of luck so far.

One solution to the $27.00 flange is a $3 steel one. Since the SS nipple threads inside this flange it is not likely to be exposed to the acid vapor. In the event a portion of it is that can be coated with something like JB Weld or steel putty as long as those products woudl not create gases of their own.

Re: My Oxalic Acid Vaporizer

I would suggest keeping the mass of your components as low as possible. The more cold metal the more heat it takes to get above the vapor poiint and the more re crystalization as the gas leaves the heat source.
As for the antiseize compound, there may be a bit of initial off gassing as the liquid component evaporates but the remainder is going to stay pretty much in place. That is what it is made to do and is slathered around all nuts, bolts, threads etc in boiler rooms around the world. It did years ago have a lot of lead powder in it but anything modern is pretty innocuous I think. If you want just use teflon joint tape. The oxalic vapor though is a whole 'nother beast! Just a mere wisp inhaled and you will be clearing your throat for a day or two.

Re: My Oxalic Acid Vaporizer

crofter, good point about the mass of the chamber and components. I am actually looking for more mass in the vaporizing chamber for the exact reason of it being a heat sink. This also causes it to remain hotter to handle longer. I do have an idea of how to solve that. keep the chamber warm but make it touchable.

As for the rest of the components they will be a 3/4 inch 45 degree elbow the same size as a galvanized pipe would be and a 1 1/2 inch length of 3/4 inch pipe. I am not sure the distance can be reduce much more than that unless the chamber itself passes through the wall. I have actually thought up a design that will work that way as well and may build it later today.

Basically it is a section of 2 inch diameter aluminum rod that fits through a hole in the box. and slides in and out like a drawer. The pocket for the acid will be a hole drilled in the side of the rod. There will be a stop at each end of the rod to prevent it from being pulled completely out or pushed to far in. The glow plug can be inserted so that it is directly under this pocket. Overall mass from glow plug to pocket of acid would be very small. And mass from vaporized acid to the air of the hive woudl be nothing. at most the acid sets in a pocket that is maybe one half to three quarters of an inch deep. think of the bowl of a smoking pipe with the acid setting in it waiting to be heated. If it works out that the glow plug can be in direct contact with the acid then there is really no mass between the glow plug and the interior of the hive. Faster vaporization since the heat is applied directly to the powder and the chamber itself does not have to be heated.

Re: My Oxalic Acid Vaporizer

You all are thinking up some great ideas. Please post some pics when you get them finished. I ordered some stainless steel tubing last night to make my nuc entrance nozzle. I'll post some pics when I have it finished.

Re: My Oxalic Acid Vaporizer

The tip of the glow plug is very corrosion resistant but not sure about specifically to Oxalic. Should be at least equal to stainless steel. That said, it may not be the best practice to have that high a temperature immediately on the oxalic. Something about it flashing to formic and CO and then not able to sublime to the fine oxalic crystal form you want deposited in the hive. Dont make too dinky of holes to charge your furnace; the oxalic powder looks nice and free flowing when you open a new container but I think it gets pretty crumby and lumpy with exposure. A glo plug is only putting out about 125 watts so you have to limit the heat loss where not needed. A couple of layers of glass cloth and a blanket of aluminum foil dont take up too much room but will slow cool down too if you want to do a series.

Re: My Oxalic Acid Vaporizer

Originally Posted by crofter

The tip of the glow plug is very corrosion resistant but not sure about specifically to Oxalic. Should be at least equal to stainless steel. That said, it may not be the best practice to have that high a temperature immediately on the oxalic. Something about it flashing to formic and CO and then not able to sublime to the fine oxalic crystal form you want deposited in the hive. Dont make too dinky of holes to charge your furnace; the oxalic powder looks nice and free flowing when you open a new container but I think it gets pretty crumby and lumpy with exposure. A glo plug is only putting out about 125 watts so you have to limit the heat loss where not needed. A couple of layers of glass cloth and a blanket of aluminum foil dont take up too much room but will slow cool down too if you want to do a series.

Great info. The tips on most glow plugs are made from Inconel. Do a search on Inconel and you will find that is some pretty tough stuff.

Re: My Oxalic Acid Vaporizer

In my experience with a crack pipe and how quickly the OA goes from vapor to CO2/water with only a slight increase of heat I believe that the OA directly contacting the glow plug should be avoided. Ideally I feel the chamber needs to be of enough mass that the OA is brought up to heat in a slower controlled manor and the reservoir should be able to hold this heat until all the OA is vaporized. It is very easy to take the OA into the CO2/water stage and a person can be unaware that this has happened rendering your treatment ineffective. That being said the delivery pipe should also be as short as possible to avoid it cooling too fast and the vapor crystallizing in this delivery pipe. The mass of metal needed to make this glow plug work may work against being able to do multiple hives quickly because of the cooling down time between hives unless the unit can be submerged in water.

Re: My Oxalic Acid Vaporizer

I have been thinking this exposed tip as well as the overheating issue over for a couple of days. So far here is my main thought. Not arguing just presenting a possibility based upon my knowledge of other materials. The tip of a glow plug is exposed to diesel fuel and any other additives of that, fuel treatments etc. IT is also exposed in an inclosed high pressure chamber. One case to show it can tolerate exposure but it also may be in part due to the environment in which it is exposed.

As for the overheateg. The OA reaches the temperature at which it will vaporize. it then vaporizes and will remove itself from the heat source. There is a very strong case that when free to vaporize it will do so eliminating any concern that ti woudl be overheated. In another example of this water will boil into steam, in in other words vapor. under open conditions the steam will not ever get hotter as it removes itself from the heat source. the only way to get steam hotter than that is to trap it in a chamber. Water in fact can be gotten far above it's boiling point without boiling if ti is put under pressure. Again it is contained. So although OA can be gotten to temperatures that will react in other ways than vaporizing. I would want to know far more about the exact conditions under which this can happen. I have a strong suspicion it cannot happen while simply exposed to the open air. iN open air the OA will have vaporized and been gone long before the element could reach to high of a temperature. Even if all of this is measure in milli seconds of time frame. the Acid will vaporize at the temperature in which it vaporizes unless it is contained in order to be exposed to temperatures higher than that. there is no concern how it will react to higher temperatures than that.

In addition there are already some designs that are demonstrated to work. At most the ideas being discussed here are alterations of those designs.

Mass is a trade off. Retained heat means the next batch is vaporized with less energy. it also means more heat retained making the unit to hot to handle. I have been toying with ideas on how to keep the heat only where it si wanted. glass cloth to insulate fro example. but to insulate just a small pocket of a chamber that holds the acid. this you have quick heating of a very small mass as well as the quick cooling of that same small mass. The heat from the glow plug only has one way to go in effect. and that is into the cup and as a result into the OA.

Anyway back to the real world.

Do to a rocky start (to many projects at once) I have finally ordered the Stainless Stell pipe fittings. Total Cost $14.36 with shipping from buyfittingsonline.com

I got
1- 3/4 inch nipple NPT
1- 3/4 inch 45 degree Elbow NPT

I will be machining an adapter to fit the Elbow and the 1 1/4 inch diameter Aluminum rod that I will make the vapor chamber out of.

I will continue to look for a way to make one of these entirely out of off the shelf parts.

I also ordered a 2 lb bottle of OA on E-bay for $12.50 including shipping.

Still to get is a 2/4 inch galvanized pipe flange for attaching the pipe to the side of the box. I estimate this to cost about $3.00. MY daughter was going by the hardware store today so hopefully she found one.

So for now I have some waiting for orders to arrive as well as some metal turning and drilling to do. I will attempt to keep this as simple as possible for those with at least limited shop availability.

Re: My Oxalic Acid Vaporizer

Good info Daniel. Sound reasonable. The only thing I can think of that might make a small difference is OA is a compound, H2C2O4. Each one of those elements has a different vaporization temp but Like you said I think it will be measured in miliseconds. Can't wait to see what you build.

Also I nearly have my smaller nuc nozzle finished. Just have to figure out the proper length. It's 3/8" stainless steel tube, press fitted in to a piece of aluminum thats threaded to fit my 1/2" pipe setup. As you can see in the pic I took some mass out of my 12v combustion chamber to help it heat faster. Just have to test it out. 2qiusd5.jpg

I had a little free time today so I carved a Maori Fish Hook out of a piece of deer antler. Now if I can just figure out how to carve a HoneyBee.awq1dl.jpg

Re: My Oxalic Acid Vaporizer

Thanks Shadow, I have been wondering about the mass of the chamber myself. It makes since to me that smaller is better both for heating up and cooling down.

The smallest aluminum rod I had laying around was 1.25 inch diameter.as it turns out I cannot mount this on my metal lathe (it is a mini 7X12) due to it holding only up to a 1 inch diameter piece. Grrrrr.

I drilled the chamber on my drill press. The glow plug fits just fine but the hole did not come out centered. I will look for a smaller piece of rod that will fit my lathe and make a new one in the future.

Interesting article. Several points caught my attention. One being that the mite kill according to his chart is nearly identical at 1.4 gram dosage as it is at 2.8. Sort of makes me wonder just how little of a dose is enough. It is a great example of showing how if enough is good more is not better.

I did pay attention to the portion about the Acid vaporizing or decomposing. It does clearly show there is a danger of decomposing the OA rather than vaporizing it by applying heat to quickly. What it does not include is how much is to much heat and in what time period.

In part due to other conversations including private ones with others. I am thinking the problem results from applying the OA to a surface or chamber that has not been allowed to cool adequately. Otherwise some of the vaporizers I have seen seem to vaporize almost immediately.

At any rate heating to quickly is definitely a concern in these designs.

I like the fish hook. The last thing I carved was quite a while back. it was a guitar pick from Mother of Pearl. I made it for a friend who was just starting to learn to play.

Re: My Oxalic Acid Vaporizer

I made up a vaporizer yesterday. I used two glow plugs so they sit either side of the chamber which is a piece of 1/2 stainless pipe about an inch and a half long with the ends closed and hole cut in the top to fill. Crude but I wanted to observe the process. I note that there is quick recrystalization on parts that are not up to temperature. Looks like hoar frost. After a while as the chamber heats, it does go off into the air. I dont think a length of pipe leading into the hive will give a dependably measured delivery. The propane heated crack pipe shows the same thing unless you heat up the discharge pipe before you heat the area with the powder. It takes a bit of fiddling to get good boil off without having it flash. It is not nice to be that up close and personal with oxalic vapor, so the electric is more user friendly. What I stuck together is not slim enough to go through a standard entrance. In a way I dont want the glow plug exposed to potentially ignite wax inside a hive as they certainly glow a bright yellow for about an inch long. Still meditating!

Re: My Oxalic Acid Vaporizer

I finished my chamber glow plug assembly as well as the connection to the box yesterday and today. I am not completely happy with it due to having to resort to some copper fittings. Without the ability to reduce the aluminum rod to be threaded to fit the SS elbow I had to find a slip fitting for the 1 1/4 inch rod. Three fittings total and nearly $30. I am not happy with the cost either.

I can fix the entire problem with using 1 inch aluminum rod in the future which then can be threaded to fit the ss pipe fittings. For now this will work for testing etc. To use it on my hives I will coat the inner surfaces of the copper fittings with epoxy such as JB weld.

Add the cost of the acid and the total is 62.20. Still more than $100 cheaper than buying one ready made.

Replacing the aluminum rod I am using with 3 inches of 1 inch aluminum rod would be about $2.50 in aluminum and eliminate nearly $20 in copper pieces. This also keeps the cost at around the $45 I consider acceptable. It does require the ability to thread the aluminum Rod to fit the Elbow. Another solution woudl be to use 3/4 inch aluminum rod and a 3/4 male thread to 3/4 inch slip adapter. This dos keep a small section of the pipe being copper though. This might be a better solution for that that need parts that just hook together though. I believe something reliable and safe can be found to coat the copper with making it a non issue.

So now I am down to the power supply. I have a battery charger but it is a smart charger that test the battery before starting the charge. it does not recognize a glow plug as a fit battery so it will not send the juice.

The easy answer of course is just yank a battery out of the car and hook up jumper cables. But I am looking at other alternatives as well. One thing that I found that got me thinking was an emergency jump starter kit. I have found several starting at around $40 listed as 300 amps or so. Anyone have any idea if one of these should work?

Re: My Oxalic Acid Vaporizer

Big Gun, For one $20 for 3 3/4 inch fittings. I am trying to keep this as low cost as possible. Second somewhere in one of the discussion on OA and vaporizers it was mentioned that the acid reacts with copper and produces a toxic gas. I am trying to avoid copper brass and galvanized steel as much as possible. I am not really sure the amount of gas produced is enough to be concerned with that is why I was willing to make an exception at all. Still the stuff is just way to high priced. Stainless Steel pipe is cheaper.

Re: My Oxalic Acid Vaporizer

Yup, Stainless is alot cheaper.
Daniel if your lathe is 7x12 why can't you turn a 1 1/4" piece? Hole through the spindle 1"? I can't see what you trying to do but I was curious. I have noticed that alot of battery chargers have the smart charge feature. Don't know about an emergency jump box. You might pick up a core trade in battery from your local parts house that still has some life in it.

Also for everyone, I found some measurements of the cup on the 12v type that slides in the front entrance.
Aluminum block is 1.700 x 1.165 x .360
Cup is machined in the block: 1.170 x 1.050 x .325
Machine the cup tight to one side leaving space for the glow plug.
Block holding glow plug is: .450 x .450 x 1.663
Threads on glow plug are machined off. A set screw in the block holds it in place.

Re: My Oxalic Acid Vaporizer

Originally Posted by crofter

I made up a vaporizer yesterday. I used two glow plugs so they sit either side of the chamber which is a piece of 1/2 stainless pipe about an inch and a half long with the ends closed and hole cut in the top to fill. Crude but I wanted to observe the process. I note that there is quick recrystalization on parts that are not up to temperature. Looks like hoar frost. After a while as the chamber heats, it does go off into the air. I dont think a length of pipe leading into the hive will give a dependably measured delivery. The propane heated crack pipe shows the same thing unless you heat up the discharge pipe before you heat the area with the powder. It takes a bit of fiddling to get good boil off without having it flash. It is not nice to be that up close and personal with oxalic vapor, so the electric is more user friendly. What I stuck together is not slim enough to go through a standard entrance. In a way I dont want the glow plug exposed to potentially ignite wax inside a hive as they certainly glow a bright yellow for about an inch long. Still meditating!

Great info. I'm getting the same "frosting" on parts that are not up to temperature. I don't know if my nuc nozzel will work or not. I'm going to work on a small compact vaporizer that will fit through the entrance. The double glow plug has gave me a few ideas.